1. Field of the Invention
The present invention relates generally to computers, and more particularly to pen computers, also known as personal digital assistants or personal communicators.
2. Related Art
There is a need today for mobile computing capability. This has resulted in the production of physically smaller and lighter personal computers, such as laptop computers, notebook computers, and tablet computers (listed in order of decreasing size and weight).
Smaller computers (such as tablet computers) generally have the same processing power and capabilities as their larger counterparts. There are, however, some disadvantages associated with smaller computers. For example, smaller computers are typically too small to accommodate an adequate, "user friendly" keyboard.
Accordingly, such smaller computers often include different mechanisms for receiving user input, such as pen sensitive displays. Smaller computers (i.e., tablet computers) which employ pen sensitive displays are called "pen computers". A pen computer is capable of recognizing user data and commands written on the pen computer's pen sensitive display. Examples of pen computers include the Newton message pad computer produced by Apple Computer, the Casio Z-7000, and the Tandy Zoomer.
Pen computers generally fall into two categories. The pen computers in the first category, such as the Newton computer, have pen sensitive displays which occupy the entire working surface. The primary advantage of these pen computers is their small size (they are a little larger than a typical paperback book) and their mobility (which results from their small size). However, it is difficult to use the pen sensitive display with these pen computers, particularly when standing or when a level and stable resting surface is unavailable. This is true, because these pen computers do not provide the user with a flat surface on which to rest her hand while writing (the user could rest her hand on the pen sensitive display, but this would result in false readings). Consequently, the user is forced to "float" her hand above the pen sensitive display, resulting in fatigue and illegible writing.
The pen computers in the second category, such as the NCR Model 3125, the Gridpad Model 2050, and the EO Models 440 and 880, are relatively large in size (approximately the size of a clip board). In these pen computers, the pen sensitive display occupies only a portion of the working surface. Accordingly, these pen computers provide the user with some surface area upon which she can rest her hand while writing. However, this surface area is not optimal, as it typically is not level with the pen sensitive display, and/or includes some protrusions (such as power and control switches, cables, ports, hinges, locking mechanisms, etc.) which impede user writing. Also, because of their larger size, these pen computers are not as mobile as the pen computers of the first category.